vector<char> findAllReportingEmployees(char M, unordered_map<char, vector<char>> &MtoE, map<char, vector<char>> &ans)
{
    if (ans.find(M) != ans.end())
    {
        return ans[M];
    }
    vector<char> E = MtoE[M];
    for (char &e : MtoE[M])
    {
        vector<char> employees = findAllReportingEmployees(e, MtoE, ans);
        for (auto &x : employees)
        {
            E.push_back(x);
        }
    }
    ans[M] = E;
    return E;
}

void findEmployees(unordered_map<char, char> &EtoM)
{
    unordered_map<char, vector<char>> MtoE;
    for (auto &etom : EtoM)
    {
        if (etom.first != etom.second)
        {
            MtoE[etom.second].push_back(etom.first);
        }
    }
    map<char, vector<char>> ans;

    for (auto &p : EtoM)
    {
        findAllReportingEmployees(p.first, MtoE, ans);
    }
    for (auto &p : ans)
    {
        cout << p.first << " -> ";
        for (auto &c : p.second)
        {
            cout << c << ", ";
        }
        cout << endl;
    }
}

void solve()
{
    unordered_map<char, char> EtoM = {{'A', 'A'}, {'B', 'A'}, {'C', 'B'}, {'D', 'B'}, {'E', 'D'}, {'F', 'E'}};
    findEmployees(EtoM);
    return;
}